mm, swap: don't use VMA based swap readahead if HDD is used as swap

[sfrench/cifs-2.6.git] / include / linux / swap.h

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 61d63379e956f21f376fa6644d6eefef8549fbc6..9c4ae6f14eeaee14eac1951f772414a6696bba0d 100644 (file)
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -400,16 +400,17 @@ extern struct page *do_swap_page_readahead(swp_entry_t fentry, gfp_t gfp_mask,
                                           struct vm_fault *vmf,
                                           struct vma_swap_readahead *swap_ra);
 
-static inline bool swap_use_vma_readahead(void)
-{
-       return READ_ONCE(swap_vma_readahead);
-}
-
 /* linux/mm/swapfile.c */
 extern atomic_long_t nr_swap_pages;
 extern long total_swap_pages;
+extern atomic_t nr_rotate_swap;
 extern bool has_usable_swap(void);
 
+static inline bool swap_use_vma_readahead(void)
+{
+       return READ_ONCE(swap_vma_readahead) && !atomic_read(&nr_rotate_swap);
+}
+
 /* Swap 50% full? Release swapcache more aggressively.. */
 static inline bool vm_swap_full(void)
 {